Based on most reviews of the A7 I've seen they often say it's AF is decent... most have a lot of the same gripes that they do with m43 systems, in that compared to a DSLR's phase detection + view finder system it's very slow, especially in low light.

That's the same drawback to any non DSLR though. Some non-DSLRs work better in certain situations than others, but none of them are perfect.

The A7 camera sets a bunch of odd expectations since it's the size of the bigger m43 cameras yet its a FF sensor that has IQ that rivals or beats DSLR FFs. This means people come at it what all sorts of expectations, each person is a bit different, and most professional camera review sites put this context very well. That if your comparing it to m43 cameras the AF is quite similar, in some ways better because of it's phase detection hybrid system, though some m43 have contrast detection systems that work a bit better in certain situations. The m43s have a bit of an edge, especially in low light, partially due to the nature of a FF vs smaller sensor.

Compared to DSLRs it's live view is faster and better... often a weak point of most DSLRs (minus the Canon 70D which is unique it's its system and technology). Though DSLRs leave the Sony A7 cameras and practically all non DSLRs (including m43 cameras) in the dust when using their viewfinder focus and especially in low light